Hair dryer

ABSTRACT

A hair dryer includes a cylindrical body; a handle disposed on a lower portion of the body; a main fan motor disposed inside the handle; and a sub fan motor disposed inside the body. The body includes a first flow passage extending along a longitudinal direction of the body in a central region of the body; and a second flow passage extending along the longitudinal direction of the body outside the first flow passage. Air introduced from outside by the main fan motor flows along the second flow passage, and air introduced from the outside by the sub fan motor flows along the first flow passage.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation application, under 35 U.S.C. § 111(a), of International Application No. PCT/KR2022/019012, filed on Nov. 29, 2022, which is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2021-0174185, filed on Dec. 7, 2021, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entirety.

BACKGROUND 1. Field

The disclosure relates to a hair dryer.

2. Description of Related Art

Generally, a hair dryer is configured to heat outside air sucked in by a fan motor with a heater 70 and discharge the heated air.

The hair dryer may be used to dry wet hair or for styling hair, such as giving waves to the hair.

Therefore, conventionally commercially available hair dryers may be broadly classified into a hair dryer for drying hair and a hair dryer for styling hair.

The hair dryer for drying hair may be used for styling hair, but there is a problem in that styling efficiency is not good.

On the other hand, the hair dryer for styling hair may also be used to dry wet hair, but there is a problem in that the efficiency of drying the hair is not good.

Accordingly, in general, users have two hair dryers for different purposes: a hair dryer for drying hair and a hair dryer for styling hair.

SUMMARY

The disclosure has been developed in order to overcome the above drawbacks and other problems associated with the conventional arrangement. An aspect of the disclosure is to provide a hair dryer capable of efficiently drying wet hair and styling hair.

According to an aspect of the disclosure, a hair dryer may include a body formed in a cylindrical shape and have a first flow passage formed to extend along a longitudinal direction of the body in a central region of the body, and a second flow passage formed to extend along the longitudinal direction of the body outside of the first flow passage; a handle being disposed on a lower portion of the body; a main fan motor to receive air introduced from outside of the hair dryer and generate a main airflow, the main fan motor being disposed inside the handle; and a sub fan motor to receive air introduced from the outside of the hair dryer and generate a sub airflow, the sub fan motor being disposed inside the body, wherein the main airflow flows along the second flow passage, and the sub airflow flows along the first flow passage.

An outlet of the first flow passage may be provided at a central portion of one end of the body, and an annular outlet of the second flow passage surrounding the outlet of the first flow passage may be provided around the outlet of the first flow passage.

The sub fan motor may be disposed at another end of the body.

The hair dryer may include a heater being disposed along the second flow passage.

The hair dryer may include a printed circuit board being disposed inside the handle and configured to supply power to the main fan motor, the sub fan motor, and the heater.

The hair dryer may include a printed circuit board being disposed inside the body and configured to supply power to the heater.

According to another aspect of the disclosure, a hair dryer may include a body formed in a cylindrical shape and having a first flow passage formed to extend along a longitudinal direction of the body in a central region of the body, and a second flow passage formed to extend along the longitudinal direction of the body outside of the first flow passage; a handle connected to the body at a substantially right angle; a main fan motor to receive air introduced from outside of the hair dryer and generate a main airflow, the main fan motor being disposed inside the handle; and a sub fan motor to receive air introduced from the outside of the hair dryer and generate a sub airflow, the sub fan motor being disposed inside the body, wherein the main airflow flows along the first flow passage, and the sub motor flows along the second flow passage.

An outlet of the first flow passage may be provided at a central portion of one end of the body, and an annular outlet of the second flow passage surrounding the outlet of the first flow passage may be provided around the outlet of the first flow passage.

The hair dryer may include a heater being disposed along the first flow passage.

The hair dryer may include a printed circuit board being disposed inside the handle and configured to supply power to the main fan motor, the sub fan motor, and the heater.

The hair dryer may include a printed circuit board being disposed inside the body and configured to supply power to the heater.

According to another aspect of the disclosure, a hair dryer may include a body having a cylindrical shape and having a first flow passage extending along a longitudinal direction of the body in a central region of the body, a second flow passage extending along the longitudinal direction of the body outside the first flow passage, and a heater being disposed along the second flow passage; a handle connected to the body at a substantially right angle; a main fan motor being disposed inside the handle; and a sub fan motor being disposed inside the body.

An outlet of the first flow passage may be provided at a central portion of one end of the body, and an annular outlet of the second flow passage surrounding the outlet of the first flow passage may be provided around the outlet of the first flow passage.

Air introduced from outside of the hair dryer and generated into a main airflow by the main fan motor may flow along the second flow passage, and air introduced from the outside of the hair dryer and generated into a sub airflow by the sub fan motor may flow along the first flow passage.

The sub airflow having a lower pressure, a lower velocity, and a larger flow rate than the main airflow.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a view illustrating a hair dryer according to an embodiment;

FIG. 2 is a cross-sectional view illustrating a hair dryer according to an embodiment;

FIG. 3 is a functional block diagram of a hair dryer according to an embodiment;

FIG. 4 is a view illustrating an outlet of the hair dryer of FIG. 2 ;

FIG. 5 is a cross-sectional view illustrating a body of the hair dryer of FIG. 2 taken along line □-□;

FIG. 6 is a cross-sectional view illustrating a state in which a main fan motor of the hair dryer of FIG. 2 operates;

FIG. 7 is a cross-sectional view illustrating a state in which a sub fan motor of the hair dryer of FIG. 2 operates;

FIG. 8 is a cross-sectional view illustrating a state in which both main fan motor and sub fan motor of the hair dryer of FIG. 2 operate;

FIG. 9 is a cross-sectional view illustrating a state in which an accessory is mounted on the hair dryer of FIG. 2 ;

FIG. 10 is a cross-sectional view illustrating a hair dryer according to another embodiment;

FIG. 11 is a view illustrating an outlet of the hair dryer of FIG. 10 ;

FIG. 12 is a cross-sectional view illustrating a body of the hair dryer of FIG. 10 taken along line □-□;

FIG. 13 is a cross-sectional view illustrating a state in which a main fan motor of the hair dryer of FIG. 10 operates;

FIG. 14 is a cross-sectional view illustrating a state in which a sub fan motor of the hair dryer of FIG. 10 operates;

FIG. 15 is a cross-sectional view illustrating a state in which both main fan motor and sub fan motor of the hair dryer of FIG. 10 operate;

FIG. 16 is a cross-sectional view illustrating a state in which an accessory is mounted on the hair dryer of FIG. 10 ;

FIG. 17 is a graph illustrating characteristics of a main fan motor and a sub fan motor used in a hair dryer according to an embodiment; and

FIG. 18 is a graph illustrating a case in which an accessory is attached to a flow passage through which an air flow generated by each of a main fan motor and a sub fan motor used in a hair dryer according to an embodiment flows.

DETAILED DESCRIPTION

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

The terms ‘first’, ‘second’, etc. may be used to describe diverse components, but the components are not limited by the terms. The terms may only be used to distinguish one component from the others. For example, without departing from the scope of the disclosure, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

The terms used in embodiments of the disclosure may be construed as commonly known to those skilled in the art unless otherwise defined.

Further, the terms ‘leading end’, ‘rear end’, ‘upper side’, ‘lower side’, ‘top end’, ‘bottom end’, etc. used in the disclosure are defined with reference to the drawings. However, the shape and position of each component are not limited by the terms.

According to a hair dryer according to an embodiment of the disclosure having the structure as described above, when styling hair, high-pressure and high-velocity airflow generated by a main fan motor and an accessory may be used, so that hair styling may be effectively performed. In addition, when drying hair, a sub fan motor configured to generate an airflow of a larger flow rate than the main fan motor may be used, so that drying hair may be effectively performed.

Therefore, a hair dryer according to an embodiment of the disclosure may effectively perform both hair drying and hair styling

Hereinafter, non-limiting example embodiments of a hair dryer according to the disclosure will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view illustrating a hair dryer according to an embodiment. FIG. 2 is a cross-sectional view illustrating a hair dryer according to an embodiment. FIG. 3 is a functional block diagram of a hair dryer according to an embodiment. FIG. 4 is a view illustrating an outlet of the hair dryer of FIG. 2 . FIG. 5 is a cross-sectional view illustrating a body of the hair dryer of FIG. 2 taken along line □-□.

Referring to FIGS. 1 to 3 , a hair dryer 1 according to an embodiment of the disclosure may include a body 10 and a handle 20.

The body 10 is formed in a substantially cylindrical shape. A first flow passage 12 and a second flow passage 11 through which an air flow passes in the longitudinal direction of the body 10 may be provided inside the body 10.

The first flow passage 12 extends along the longitudinal direction of the body 10 in the central region of the body 10. The second flow passage 11 extends outside the first flow passage 12 along the longitudinal direction of the body 10. Accordingly, the first flow passage 12 may be referred to as a central flow passage of the body 10, and the second flow passage 11 may be referred to as a peripheral flow passage.

At one end of the body 10, that is, at the front end of the body 10, an outlet 12 a of the first flow passage 12 (hereinafter, referred to as a first flow passage outlet) through which the airflow passing through the first flow passage 12 is discharged and an outlet 11 a of the second flow passage 11 (hereinafter, referred to as a second flow passage outlet) through which the airflow passing through the second flow passage 12 is discharged may be provided. In other words, the first flow passage outlet 12 a may be provided at the center of the one end of the body 10, and the annular second flow passage outlet 11 a surrounding the first flow passage outlet 12 a may be provided around the first flow passage outlet 12 a.

At the other end of the body 10 opposite to the one end of the body 10 provided with the first flow passage outlet 12 a and the second flow passage outlet 11 a, that is, at the rear end of the body 10, a rear inlet 14 through which outside air is introduced into the body 10 may be provided.

The rear inlet 14 may be formed in various shapes as long as outside air can be introduced into the body 10. For example, the rear inlet 14 may be formed as a plurality of through holes formed on the rear surface of the body 10.

A rear filter 15 formed to filter the outside air introduced through the rear inlet 14 may be disposed at the rear end of the body 10. The rear filter 15 may be disposed in the body 10 adjacent to the rear inlet 14.

A sub fan motor 30 configured to generate a high-flow rate airflow may be disposed inside the body 10. The sub fan motor 30 may be disposed adjacent to the rear inlet 14 at the rear end of the body 10. In other words, the sub fan motor 30 may be disposed inside the body 10 opposite to the first flow passage outlet 12 a and the second flow passage outlet 11 a.

The handle 20 is disposed on the lower portion of the body 10 and is formed so that the user may manipulate the hair dryer 1 by holding the handle 20 by hand. The handle 20 may be connected to the body 10 at a substantially right angle.

A main fan motor 40 configured to generate a high-pressure and high-velocity airflow may be disposed inside the handle 20.

A lower inlet 24 through which outside air is introduced into the inside of the handle 20 may be provided at a lower end portion of the handle 20. The lower inlet 24 may be formed in various shapes as long as outside air can be introduced into the handle 20. For example, the lower inlet 24 may be formed as a plurality of through holes formed on the outer circumferential surface of the lower end portion of the handle 20.

A lower filter 25 formed to filter the outside air flowing into the lower inlet 24 may be disposed in the handle 20. The lower filter 25 may be disposed on the inside of the handle 20 adjacent to the lower inlet 24.

The second flow passage 11 is formed inside the body 10, and includes the second flow passage outlet 11 a provided at the front end of the body. The second flow passage 11 is formed in the longitudinal direction of the body 10. The main fan motor 40 is connected to the second flow passage 11 so that the airflow generated by the main fan motor 40 may flow through the second flow passage 11.

The main fan motor 40 may be connected to the lower portion of the second flow passage 11 formed inside the body 10. To this end, a connection passage 21 connecting the main fan motor 40 and the second flow passage 11 may be provided at the upper portion of the handle 20. Accordingly, the airflow generated by the main fan motor 40 may move to the second flow passage outlet 11 a through the connection passage 21 and the second flow passage 11.

The first flow passage 12 is formed inside the second flow passage 11, and includes the first flow passage outlet 12 a provided at the front end of the body 10. As illustrated in FIG. 4 , the first flow passage outlet 12 a may be provided at the center of the second flow passage outlet 11 a. Accordingly, the second flow passage outlet 11 a has an annular shape, and the first flow passage outlet 12 a has a circular shape positioned inside the second flow passage outlet 11 a. The first flow passage outlet 12 a and the second flow passage outlet 11 a may be concentrically disposed.

The first flow passage 12 may be formed in a hollow cylindrical shape, and may be disposed in the center of the second flow passage 11. Accordingly, as illustrated in FIGS. 2 and 5 , the second flow passage 11 may be formed in a cylindrical shape having an annular cross-section, and the first flow passage 12 may be positioned at the center of the second flow passage 11.

The sub fan motor 30 may be disposed at the rear end of the body 10, and may be connected to the first flow passage 12 formed inside the second flow passage 11. The sub fan motor 30 may be disposed behind the handle 20 based on the front end of the body 10.

The sub fan motor 30 may be formed to generate a high-flow rate airflow, and may be connected to the rear end of the first flow passage 12. Accordingly, the airflow generated by the sub fan motor 30 may be moved to the first flow passage outlet 12 a through the first flow passage 12.

The first flow passage 12 and the second flow passage 11 may be formed by an inner duct 50 disposed inside the body 10.

Referring to FIG. 2 , the inner duct 50 is disposed inside the body 10, and may be formed in a hollow cylindrical shape having a diameter smaller than the inner diameter of the body 10. Both ends of the inner duct 50 are open.

The inner duct 50 is disposed so that one end of the inner duct 50 is positioned on the same plane as the front end of the body 10.

The other end of the inner duct 50 may be formed adjacent to the sub fan motor 30 to be fixed to the inner circumferential surface of the body 10. To this end, the other end of the inner duct 50 may include a connection part 51 connected to the inner circumferential surface of the body 10.

For example, the connection part 51 of the inner duct 50 may be formed in a shape that spreads from the other end of the inner duct 50 to the inner circumferential surface of the body 10. In other words, the connection part 51 of the inner duct 50 may be formed in a funnel shape. One end of the connection part 51 of the inner duct 50 is in contact with the inner circumferential surface of the body 10, and is disposed in the body 10 so that air does not pass between the body 10 and the connection part 51 of the inner duct 50.

The second flow passage 11 is formed as a space between the inner circumferential surface of the body 10 and the outer circumferential surface of the inner duct 50. One end of the second flow passage 11 is open and the other end of the second flow passage 11 is closed. The one end of the second flow passage 11 forms the second flow passage outlet 11 a provided at the front end of the body 10. The other end of the second flow passage 11 is blocked by the connection part 51 of the inner duct 50.

The first flow passage 12 is formed as an inner space of the inner duct 50. Accordingly, both ends of the first flow passage 12 are open. One end of the first flow passage 12 forms the first flow passage outlet 12 a provided at the front end of the body 10. The other end of the first flow passage 12 communicates with the sub fan motor 30. In other words, the other end of the first flow passage 12 is connected to a back space of the body 10 in which the sub fan motor 30 is disposed. Accordingly, when the sub fan motor 30 operates, the airflow generated by the sub fan motor 30 passes through the first flow passage 12, and then is discharged to the outside through the first flow passage outlet 12 a.

The connection passage 21 connecting the second flow passage 11 and the main fan motor 40 may be formed by a connection duct 60 disposed inside the handle 20.

The connection duct 60 may be provided at the upper portion of the handle 20 disposed on the lower portion of the body 10. The connection duct 60 is provided inside the handle 20, and may be formed to connect the second flow passage 11 and the main fan motor 40. In other words, the connection duct 60 may be formed to guide the airflow generated by the main fan motor 40 to the second flow passage 11.

The lower end of the connection duct 60 is connected to the main fan motor 40, and the upper end of the connection duct 60 is connected to the lower portion of the body 10. An opening 17 to which the upper end of the connection duct 60 is connected may be provided on the lower surface of the body. The opening 17 of the body 10 communicates with the second flow passage 11. Accordingly, the airflow generated by the main fan motor 40 may move to the second flow passage 11 through the connection duct 60 and the opening 17.

As described above, because the first flow passage 12 and the second flow passage 11 are partitioned by the inner duct 50, the airflow passing through the first flow passage 12 and the airflow passing through the second flow passage 11 do not interfere with each other.

A heater 70 may be disposed in the second flow passage 11. The heater 70 is formed to heat the airflow passing through the second flow passage 11. The heater 70 may be disposed in the second flow passage 11 adjacent to the second flow passage outlet 11 a. The heater 70 is formed to allow airflow to pass therethrough. The airflow may pass through the heater 70 and be discharged to the outside through the second flow passage outlet 11 a.

In other words, the heater 70 may be disposed in a space between the body 10 and the inner duct 50. The heater 70 may be disposed on the outer circumferential surface of the inner duct 50 adjacent to the second flow passage outlet 11 a.

The main fan motor 40 may be configured to generate a high-pressure and high-velocity airflow. The main fan motor 40 may be configured to generate an airflow having a higher pressure and higher velocity than the sub fan motor 30.

The main fan motor 40 may include a main fan and a main motor configured to rotate the main fan. The main fan has a small diameter, and the main motor is configured to rotate at a high rotation speed (rpm). Accordingly, the main fan motor 40 has a small diameter and may rotate at a high rotation speed.

For example, the main fan may have the diameter of 20 mm to 35 mm, and the rotation speed of the main motor may be 100,000 rpm to 150,000 rpm.

The sub fan motor 30 may be formed to generate a high-flow rate airflow. The sub fan motor 30 may be formed to generate an airflow having a higher flow rate than main fan motor 40.

The sub fan motor 30 may include a sub fan and a sub motor configured to rotate the sub fan. The sub fan has a larger diameter than the main fan. The sub motor is configured to rotate at a low rotation speed. In other words, the sub motor is configured to rotate at a rotation speed lower than the rotation speed of the main motor. Accordingly, the sub fan motor 30 has a large diameter and may rotate at a low rotation speed.

For example, the diameter of the sub fan may be 40 mm to 100 mm, and the rotation speed of the sub motor may be 10,000 rpm to 50,000 rpm.

Because the main fan motor 40 has a small diameter, the main fan motor 40 may be disposed inside the handle 20. Because the sub fan motor 30 has a larger diameter than the main fan motor 40, the sub fan motor 30 may not be disposed in the handle 20, but may be disposed inside the body 10.

In addition, the hair dryer 1 may include a printed circuit board 80 configured to supply power to the main fan motor 40, the sub fan motor 30, and the heater 70. Also, the printed circuit board 80 may be configured to control the main fan motor 40, the sub fan motor 30, and the heater 70.

The printed circuit board 80 may be disposed in at least one of the body 10 and the handle 20.

Here, the printed circuit board 80 refers to a printed circuit board assembly including various electronic components and a substrate constituting an electronic circuit capable of supplying power to and controlling the main fan motor 40, the sub fan motor 30, and the heater 70.

In the case of this embodiment illustrated in FIG. 2 , the printed circuit board 80 may include a body printed circuit board 81 disposed in the body 10 and a handle printed circuit board 82 disposed in the handle 20.

The body printed circuit board 81 may be disposed at the rear end of the second flow passage 11 adjacent to the sub fan motor 30. In other words, the body printed circuit board 81 may be disposed in a space between the body 10 and the inner duct 50. The body printed circuit board 81 may be disposed adjacent to the connection part 51 of the inner duct 50.

The body printed circuit board 81 may be disposed to be spaced apart from the heater 70 by a predetermined distance. When the body printed circuit board 81 is spaced apart from the heater 70 by a predetermined distance, the effect of the heat of the heater 70 on the body printed circuit board 81 may be minimized.

The body printed circuit board 81 may be disposed so as not to prevent the airflow generated by the main fan motor 40 from flowing into the second flow passage 11. For example, the body printed circuit board 81 may be disposed outside the opening 17 of the body 10 that communicates the second flow passage 11 and the connection passage 21.

Because the second flow passage 11 has an annular cross-section, the body printed circuit board 81 disposed in the second flow passage 11 is formed in an annular shape corresponding to the second flow passage 11.

As an example, the body printed circuit board 81 may be configured to supply power to the sub fan motor 30 and the heater 70, and control the sub fan motor 30 and the heater 70.

The handle printed circuit board 82 may be disposed inside the handle 20. The handle printed circuit board 82 may be disposed in the inner space of the handle 20 so as not to interfere with the main fan motor 40. As an example, the handle printed circuit board 82 may be configured to control the main fan motor 40.

The handle printed circuit board 82 may be electrically connected to a main fan motor switch 83, a sub fan motor switch 84, and a heater switch 86 disposed on the handle 20. Alternatively, the main fan motor switch 83, the sub fan motor switch 84, and the heater switch 86 may be disposed on the handle printed circuit board 82.

The main fan motor switch 83 may be configured to turn on/off the main fan motor 40. Also, the main fan motor switch 83 may be configured to control the speed of the main fan motor 40 to adjust the strength of the airflow discharged from the second flow passage outlet 11 a.

The sub fan motor switch 84 may be configured to turn on/off the sub fan motor 30. Also, the sub fan motor switch 84 may be configured to control the speed of the sub fan motor 30 to adjust the strength of the airflow discharged from the first flow passage outlet 12 a.

The heater switch 86 may be configured to turn on/off the heater 70. Also, the heater switch 86 may be configured to control the heat generated by the heater 70.

Hereinafter, the operation of the hair dryer 1 according to an embodiment of the disclosure will be described in detail with reference to FIGS. 6 to 8 .

The main fan motor 40 and the sub fan motor 30 provided in the hair dryer 1 according to an embodiment may operate individually, and the two motors 30 and 40 may operate simultaneously.

FIG. 6 is a cross-sectional view illustrating a state in which a main fan motor of the hair dryer of FIG. 2 operates. At this time, the sub fan motor 30 does not operate.

When the main fan motor 40 is operated using the main fan motor switch 83, an airflow is generated by the main fan motor 40. In detail, when the main fan motor 40 rotates, outside air is introduced into the handle 20 through the lower inlet 24, and the introduced outside air is formed as a high-pressure and high-velocity airflow (hereinafter, referred to as a main airflow) by the main fan motor 40.

Referring to FIG. 6 , the main airflow moves to the second flow passage 11 through the connection passage 21. The main airflow moving to the second flow passage 11 is discharged to the outside of the body 10 through the second flow passage outlet 11 a. In other words, when the main fan motor 40 operates, the high-pressure and high-velocity airflow is discharged from the second flow passage outlet 11 a provided at the front end of the body 10. At this time, the airflow is not discharged from the first flow passage outlet 12 a provided inside the second flow passage outlet 11 a.

Then, the user may style the hair using the high-pressure and high-velocity airflow discharged from the second flow passage outlet 11 a.

FIG. 7 is a cross-sectional view illustrating a state in which a sub fan motor of the hair dryer of FIG. 2 operates. At this time, the main fan motor 40 is in a non-operational state.

When the sub fan motor 30 is operated using the sub fan motor switch 84, an airflow is generated by the sub fan motor 30. In detail, when the sub fan motor 30 rotates, outside air flows into the body 10 through the rear inlet 14, and the introduced outside air is formed as a high-flow rate airflow (hereinafter referred to as a sub airflow) by the sub fan motor 30.

Referring to FIG. 7 , the sub airflow generated by the sub fan motor 30 moves to the first flow passage outlet 12 a through the first flow passage 12, and is discharged to the outside through the first flow passage outlet 12 a. In other words, when the sub fan motor 30 operates, a high-flow rate airflow is discharged from the first flow passage outlet 12 a provided at the front end of the body 10. At this time, the airflow is not discharged from the second flow passage outlet 11 a provided outside the first flow passage outlet 12 a.

Then, the user may dry the hair by using the high-flow rate airflow discharged from the first flow passage outlet 12 a.

Compared to the main airflow, the sub airflow has a lower pressure and velocity and a larger flow rate, so the sub airflow is effective for drying wet hair. Conversely, the main airflow has a higher pressure and velocity and a smaller flow rate than the sub airflow, so the main airflow is effective for styling hair, but not effective for drying wet hair.

FIG. 8 is a cross-sectional view illustrating a state in which both main fan motor and sub fan motor of the hair dryer of FIG. 2 operate.

Referring to FIG. 8 , the high-pressure and high-velocity main airflow generated by the main fan motor 40 passes through the connection passage 21 and the second flow passage 11, and then is discharged to the outside through the second flow passage outlet 11 a.

In addition, the high-flow rate sub airflow generated by the sub fan motor 30 passes through the first flow passage 12, and then is discharged to the outside through the first flow passage outlet 12 a.

In other words, when both the main fan motor 40 and the sub fan motor 30 operate, the airflows are discharged from both the second flow passage outlet 11 a and the first flow passage outlet 12 a provided at the front end of the body 10. At this time, the high-pressure and high-velocity main airflow is discharged from the second flow passage outlet 11 a, and the high-flow rate sub airflow is discharged from the first flow passage outlet 12 a.

As such, when both the main fan motor 40 and the sub fan motor 30 operate, a larger amount of airflow is discharged from the front end of the body 10 than when only the sub fan motor 30 operates, so wet hair may be dried more efficiently.

The front end of the body 10 of the hair dryer 1 according to an embodiment of the disclosure may be equipped with an accessory 100 for styling hair.

FIG. 9 is a cross-sectional view illustrating a state in which an accessory is mounted on the hair dryer of FIG. 2 .

Referring to FIG. 9 , the accessory 100 for styling hair may be detachably mounted to the front end of the body 10. The accessory 100 may be formed to style hair using the airflow discharged from the second flow passage outlet 11 a. Because the second flow passage outlet 11 a discharges the high-pressure and high-velocity airflow, it is possible to effectively style the hair using the accessory 100.

In this case, the accessory 100 may be formed so that the airflow discharged from the first flow passage outlet 12 a does not pass the accessory 100. Accordingly, when the sub fan motor 30 operates, the high-flow rate airflow passing through the first flow passage 12 is not discharged through the accessory 100.

Hereinafter, a hair dryer 1 according to another embodiment of the disclosure will be described in detail with reference to FIGS. 10 to 12 .

FIG. 10 is a cross-sectional view illustrating a hair dryer according to another embodiment. FIG. 11 is a view illustrating an outlet of the hair dryer of FIG. 10 . FIG. 12 is a cross-sectional view illustrating a body of the hair dryer of FIG. 10 taken along line □-□.

Referring to FIGS. 10 to 12 , a hair dryer 1 according to an embodiment of the disclosure may include a body 10 and a handle 20.

The body 10 is formed in a substantially cylindrical shape. A first flow passage 12 and a second flow passage 11 through which an airflow passes in the longitudinal direction of the body 10 may be provided inside the body 10.

The first flow passage 12 extends along the longitudinal direction of the body 10 in the central region of the body 10. The second flow passage 11 extends outside the first flow passage 12 in the longitudinal direction of the body 10. Accordingly, the first flow passage 12 may be referred to as a central flow passage of the body 10, and the second flow passage 11 may be referred to as a peripheral flow passage.

At one end of the body 10, that is, at the front end of the body 10, an outlet 12 a of the first flow passage 12 (hereinafter, referred to as a first flow passage outlet) through which the airflow passing through the first flow passage 12 is discharged and an outlet 11 a of the second flow passage 11 (hereinafter, referred to as a second flow passage outlet) through which the airflow passing through the second flow passage 12 is discharged may be provided. In other words, the first flow passage outlet 12 a may be provided at the center of the one end of the body 10, and the annular second flow passage outlet 11 a surrounding the first flow passage outlet 12 a may be provided around the first flow passage outlet 12 a.

At the rear end of the body 10 opposite to the front end of the body 10 provided with the first flow passage outlet 12 a and the second flow passage outlet 11 a, a rear inlet 14 through which outside air is introduced into the body 10 may be provided.

The rear inlet 14 may be formed in various shapes as long as outside air can be introduced into the body 10. For example, the rear inlet 14 may be formed as a plurality of through holes formed on the rear surface of the body 10.

A rear filter 15 configured to filter the outside air introduced through the rear inlet 14 may be disposed at the rear end of the body 10. The rear filter 15 may be disposed in the body 10 adjacent to the rear inlet 14.

A sub fan motor 30 configured to generate a high-flow rate airflow may be disposed inside the body 10. The sub fan motor 30 may be disposed adjacent to the rear inlet 14 at the rear end of the body 10. In other words, the sub fan motor 30 may be disposed inside the body 10 opposite to the first flow passage outlet 12 a and the second flow passage outlet 11 a.

The handle 20 is disposed on the lower portion of the body 10 and is formed so that the user may manipulate the hair dryer 1 by holding the handle 20 by hand. The handle 20 may be connected to the body 10 at an approximately right angle.

A main fan motor 40 configured to generate a high-pressure and high-velocity airflow may be disposed inside the handle 20.

A lower inlet 24 through which outside air is introduced into the inside of the handle 20 may be provided at a lower end portion of the handle 20. The lower inlet 24 may be formed in various shapes as long as outside air can be introduced into the handle 20. For example, the lower inlet 24 may be formed as a plurality of through holes formed on the outer circumferential surface of the lower end portion of the handle 20.

A lower filter 25 configured to filter the outside air flowing into the lower inlet 24 may be disposed in the handle 20. The lower filter 25 may be disposed on the handle 20 adjacent to the lower inlet 24.

The second flow passage 11 is formed inside the body 10, and includes the second flow passage outlet 11 a provided at the front end of the body 10. The second flow passage 11 is formed in the longitudinal direction of the body 10. The sub fan motor 30 is connected to the second flow passage 11 so that the airflow generated by the sub fan motor 40 may flow through the second flow passage 11.

The sub fan motor 30 may be disposed at the rear end of the body 10, and may be connected to the second flow passage 11. The sub fan motor 30 is configured to generate a high-flow rate airflow, and may be connected to the rear end of the second flow passage 11. Accordingly, the airflow generated by the sub fan motor 30 may pass through the second flow passage 11, and then may be discharged through the second flow passage outlet 11 a.

The first flow passage 12 is formed inside the second flow passage 11, and includes the first flow passage outlet 12 a provided at the front end of the body 10. As illustrated in FIG. 11 , the first flow passage outlet 12 a may be provided at the center of the second flow passage outlet 11 a. Accordingly, the second flow passage outlet 11 a has an annular shape, and the first flow passage outlet 12 a has a circular shape positioned inside the second flow passage outlet 11 a. The first flow passage outlet 12 a and the second flow passage outlet 11 a may be concentrically disposed.

The first flow passage 12 may be formed in a hollow cylindrical shape, and may be disposed in the center of the second flow passage 11. Accordingly, as illustrated in FIGS. 10 and 12 , the second flow passage 11 may be formed in a cylindrical shape having an annular cross-section, and the first flow passage 12 may be positioned at the center of the second flow passage 11.

The main fan motor 40 may be connected to the lower portion of the first flow passage 12 formed inside the body 10. To this end, a connection passage 21 connecting the main fan motor 40 and the first flow passage 12 may be provided at the upper portion of the handle 20. Accordingly, the airflow generated by the main fan motor 40 may be discharged through the first flow passage outlet 12 a through the connection passage 21 and the first flow passage 12.

The first flow passage 12 and the second flow passage 11 may be formed by an inner duct 50 disposed inside the body 10.

Referring to FIGS. 10 and 12 , the inner duct 50 is disposed inside the body 10, and may be formed in a hollow cylindrical shape having a diameter smaller than the inner diameter of the body 10. One end of the inner duct 50 is open, and the other end thereof is closed.

The inner duct 50 is disposed so that one end of the inner duct 50 is positioned on the same plane as the front end of the body 10.

The other end of the inner duct 50 is disposed adjacent to the sub fan motor 30, and is blocked so that an airflow generated by the sub fan motor 30 is not introduced into the inner duct 50.

The second flow passage 11 is formed as a space between the inner circumferential surface of the body 10 and the outer circumferential surface of the inner duct 50. Both ends of the second flow passage 11 are open. One end of the second flow passage 11 forms the second flow passage outlet 11 a provided at the front end of the body 10. The other end of the second flow passage 11 communicates with the sub fan motor 30. In other words, the other end of the second flow passage 11 is connected to a back space of the body 10 in which the sub fan motor 30 is disposed. Accordingly, when the sub fan motor 30 operates, the airflow generated by the sub fan motor 30 passes through the second flow passage 11, and then is discharged to the outside through the second flow passage outlet 11 a.

The first flow passage 12 is formed as an inner space of the inner duct 50. Accordingly, one end of the first flow passage 12 is open and the other end thereof is closed. One end of the first flow passage 12 forms the first flow passage outlet 12 a provided at the front end of the body 10.

The connection passage 21 connecting the first flow passage 12 and the main fan motor 40 may be formed by a connection duct 60 disposed inside the handle 20.

The connection duct 60 may be provided at the upper portion of the handle 20 disposed on the lower portion of the body 10. The connection duct 60 is provided inside the handle 20, and is formed to penetrate the lower surface of the body 10 to connect the first flow passage 12 and the main fan motor 40.

In other words, the connection duct 60 may be formed to guide the airflow generated by the main fan motor 40 to the first flow passage 12. Accordingly, the connection duct 60 is connected to the inner duct 50 across the lower portion of the second flow passage 11.

The lower end of the connection duct 60 is connected to the main fan motor 40, and the upper end of the connection duct 60 is connected to the lower portion of the inner duct 50. An opening 57 to which the upper end of the connection duct 60 is connected may be provided on the lower surface of the inner duct 50. The opening 57 of the inner duct 50 communicates with the first flow passage 12. Accordingly, the airflow generated by the main fan motor 40 may move to the first flow passage 12 through the connection duct 60 and the opening 57.

In addition, the airflow generated by the sub fan motor 30 and moving to the lower portion of the second flow passage 11 may move along the outer surface of the connection duct 60, and then may be discharged to the outside through the second flow passage outlet 11 a.

As described above, because the first flow passage 12 and the second flow passage 11 are partitioned by the inner duct 50, the airflow passing through the first flow passage 12 and the airflow passing through the second flow passage 11 do not interfere with each other.

A heater 70 may be disposed in the first flow passage 12. The heater 70 is formed to heat the airflow passing through the first flow passage 12. The heater 70 may be disposed in the first flow passage 12 adjacent to the first flow passage outlet 12 a. The heater 70 is formed to allow airflow to pass therethrough.

In other words, the heater 70 may be disposed in the inner space of the inner duct 50. The heater 70 may be disposed inside the inner duct 50 adjacent to the first flow passage outlet 12 a.

The main fan motor 40 may be configured to generate a high-pressure and high-velocity airflow. The main fan motor 40 may be configured to generate an airflow having a higher pressure and higher velocity than the sub fan motor 30.

The main fan motor 40 may include a main fan and a main motor configured to rotate the main fan. The main fan has a small diameter, and the main motor is configured to rotate at a high rotation speed (rpm). Accordingly, the main fan motor 40 has a small diameter and may rotate at a high rotation speed.

For example, the diameter of the main fan may be 20 mm to 35 mm, and the rotation speed of the main motor may be 100,000 rpm to 150,000 rpm.

The sub fan motor 30 may be configured to generate a high-flow rate airflow. The sub fan motor 30 may be formed to generate an airflow having a higher flow rate than main fan motor 40.

The sub fan motor 30 may include a sub fan and a sub motor configured to rotate the sub fan. The sub fan has a larger diameter than the main fan. The sub motor is configured to rotate at a low rotation speed. In other words, the sub motor is configured to rotate at a rotation speed lower than the rotation speed of the main motor. Accordingly, the sub fan motor 30 has a large diameter and may rotate at a low rotation speed.

For example, the diameter of the sub fan may be 40 mm to 100 mm, and the rotation speed of the sub motor may be 10,000 rpm to 50,000 rpm.

Because the main fan motor 40 has a small diameter, the main fan motor 40 may be disposed inside the handle 20. Because the sub fan motor 30 has a larger diameter than the main fan motor 40, the sub fan motor 30 may not be disposed in the handle 20, but may be disposed inside the body 10.

In addition, the hair dryer 1 may include a printed circuit board 80 configured to supply power to the main fan motor 40, the sub fan motor 30, and the heater 70. Also, the printed circuit board 80 may be configured to control the main fan motor 40, the sub fan motor 30, and the heater 70.

The printed circuit board 80 may be disposed in at least one of the body 10 and the handle 20.

Here, the printed circuit board 80 refers to a printed circuit board assembly including various electronic components and a substrate constituting an electronic circuit configured to supply power to and to control the main fan motor 40, the sub fan motor 30, and the heater 70.

In the case of this embodiment illustrated in FIG. 10 , the printed circuit board 80 may include a body printed circuit board 81 disposed in the body 10 and a handle printed circuit board 82 disposed in the handle 20.

The body printed circuit board 81 may be disposed at the rear end of the first flow passage 12 adjacent to the sub fan motor 30. In other words, the body printed circuit board 81 may be disposed inside the inner duct 50. The body printed circuit board 81 may be disposed adjacent to the rear end of the inner duct 50.

The body printed circuit board 81 may be disposed to be spaced apart from the heater 70 by a predetermined distance. When the body printed circuit board 81 is spaced apart from the heater 70 by a predetermined distance, the effect of the heat of the heater 70 on the body printed circuit board 81 may be minimized.

The body printed circuit board 81 may be disposed so as not to prevent the airflow generated by the main fan motor 40 from flowing into the first flow passage 12. For example, the body printed circuit board 81 may be disposed outside the opening 57 of the inner duct 50 that communicates the first flow passage 12 and the connection passage 21.

Because the body printed circuit board 81 is disposed in the first flow passage 12 having a circular cross-section, the body printed circuit board 81 may be formed in a disk shape corresponding to the first flow passage 12.

For example, the body printed circuit board 81 may be configured to supply power to the sub fan motor 30 and the heater 70, and control the sub fan motor 30 and the heater 70.

The handle printed circuit board 82 may be disposed inside the handle 20. The handle printed circuit board 82 may be disposed in the inner space of the handle 20 so as not to interfere with the main fan motor 40.

For example, the handle printed circuit board 82 may be configured to supply power to and control the main fan motor 40.

The handle printed circuit board 82 may be electrically connected to a main fan motor switch 83, a sub fan motor switch 84, and a heater switch 86 disposed on the handle 20. Alternatively, the main fan motor switch 83, the sub fan motor switch 84, and the heater switch 86 may be disposed on the handle printed circuit board 82.

The main fan motor switch 83 may be configured to turn on/off the main fan motor 40. Also, the main fan motor switch 83 may be configured to control the speed of the main fan motor 40 to adjust the strength of the airflow discharged from the first flow passage outlet 12 a.

The sub fan motor switch 84 may be configured to turn on/off the sub fan motor 30. Also, the sub fan motor switch 84 may be configured to control the speed of the sub fan motor 30 to adjust the strength of the airflow discharged from the second flow passage outlet 11 a.

The heater switch 86 may be configured to turn on/off the heater 70. Also, the heater switch 86 may be configured to control the heat generated by the heater 70.

Hereinafter, the operation of the hair dryer 1 according to an embodiment of the disclosure will be described in detain with reference to FIGS. 13 to 15 .

The main fan motor 40 and the sub fan motor 30 provided in the hair dryer 1 according to an embodiment may operate individually, and the two motors 30 and 40 may operate simultaneously.

FIG. 13 is a cross-sectional view illustrating a state in which a main fan motor of the hair dryer of FIG. 10 operates. At this time, the sub fan motor 30 is in a non-operational state.

When the main fan motor 40 is operated using the main fan motor switch 83, an airflow is generated by the main fan motor 40. In detail, when the main fan motor 40 rotates, outside air is introduced into the handle 20 through the lower inlet 24, and the introduced outside air is formed as a high-pressure and high-velocity airflow (hereinafter, referred to as a main airflow) by the main fan motor 40.

Referring to FIG. 13 , the main airflow moves to the first flow passage 12 through the connection passage 21. The main airflow moving to the first flow passage 12 is discharged to the outside of the body 10 through the first flow passage outlet 12 a. In other words, when the main fan motor 40 operates, the high-pressure and high-velocity airflow is discharged from the first flow passage outlet 12 a provided at the front end of the body 10. At this time, the airflow is not discharged from the second flow passage outlet 11 a provided outside the first flow passage outlet 12 a.

Then, the user may style the hair using the high-pressure and high-velocity airflow discharged from the first flow passage outlet 12 a.

FIG. 14 is a cross-sectional view illustrating a state in which a sub fan motor of the hair dryer of FIG. 10 operates. At this time, the main fan motor 40 is in a non-operational state.

When the sub fan motor 30 is operated using the sub fan motor switch 84, an airflow is generated by the sub fan motor 30. In detail, when the sub fan motor 30 rotates, outside air flows into the body 10 through the rear inlet 14, and the introduced outside air is formed as a high-flow rate airflow (hereinafter referred to as a sub airflow) by the sub fan motor 30.

Referring to FIG. 14 , the sub airflow generated by the sub fan motor 30 moves to the second flow passage outlet 11 a through the second flow passage 11, and is discharged to the outside through the second flow passage outlet 11 a. In other words, when the sub fan motor 30 operates, a high-flow rate airflow is discharged from the second flow passage outlet 11 a provided at the front end of the body 10. At this time, the airflow is not discharged from the first flow passage outlet 12 a provided inside the second flow passage outlet 11 a.

Then, the user may dry the hair by using the high-flow rate airflow discharged from the second flow passage outlet 11 a.

Compared to the main airflow, the sub airflow has a lower pressure and velocity and a larger flow rate, so the sub airflow is effective for drying wet hair. Conversely, the main airflow has a higher pressure and velocity and a smaller flow rate than the sub airflow, so the main airflow is effective for styling hair, but not effective for drying wet hair.

FIG. 15 is a cross-sectional view illustrating a state in which both main fan motor and sub fan motor of the hair dryer of FIG. 10 operate.

Referring to FIG. 15 , the high-pressure and high-velocity main airflow generated by the main fan motor 40 passes through the connection passage 21 and the first flow passage 12, and then is discharged to the outside through the first flow passage outlet 12 a.

In addition, the high-flow rate sub airflow generated by the sub fan motor 30 passes through the second flow passage 11, and then is discharged to the outside through the second flow passage outlet 11 a.

In other words, when both the main fan motor 40 and the sub fan motor 30 operate, airflows are discharged from both the first flow passage outlet 12 a and the second flow passage outlet 11 a provided at the front end of the body 10. At this time, a high-pressure and high-velocity main airflow is discharged from the first flow passage outlet 12 a, and a high-flow rate sub airflow is discharged from the second flow passage outlet 11 a.

As such, when both the main fan motor 40 and the sub fan motor 30 operate, a larger amount of airflow is discharged from the front end of the body 10 than when only the sub fan motor 30 operates, so wet hair may be dried more efficiently.

The front end of the body 10 of the hair dryer 1 according to an embodiment of the disclosure may be equipped with an accessory 100 for styling hair.

FIG. 16 is a cross-sectional view illustrating a state in which an accessory is mounted on the hair dryer of FIG. 10 .

Referring to FIG. 16 , the accessory 100 for styling hair may be detachably mounted to the front end of the body 10. The accessory 100 may be formed to style hair using the airflow discharged from the first flow passage outlet 12 a. Because the high-pressure and high-velocity airflow is discharged from the first flow passage outlet 12 a, hair styling may be effectively performed using the accessory 100.

In this case, the accessory 100 may be formed to have a smaller diameter than the second flow passage outlet 11 a so that the airflow discharged from the second flow passage outlet 11 a does not pass the accessory 100. Accordingly, when the sub fan motor 30 operates, the high-flow rate airflow passing through the second flow passage 11 is not discharged through the accessory 100.

Hereinafter, the reason for connecting the accessory 100 for hair styling to the flow passage through which the high-pressure and high-velocity airflow generated by the main fan motor 40 flows will be described with reference to FIGS. 17 and 18 .

FIG. 17 is a graph illustrating characteristics of a main fan motor and a sub fan motor used in a hair dryer according to an embodiment. For reference, FIG. 17 illustrates the relationship between the static pressure and the flow rate of the airflow when the airflow generated by each of the main fan motor 40 and the sub fan motor 30 flows the flow passage.

In FIG. 17 , the vertical axis represents the static pressure, and the horizontal axis represents the flow rate. Curve A represents the characteristics of the sub fan motor 30, and curve B represents the characteristics of the main fan motor 40.

Referring to FIG. 17 , because the sub fan motor 30 has the characteristics of a large diameter and a low rotation speed, as illustrated in the curve A, the change in the flow rate according to the static pressure change is large. When the flow rate is large, the static pressure of the sub fan motor 30 is higher than that of the main fan motor 40. Accordingly, when the cross-sectional area of the outlet of the flow passage which the airflow generated by the sub fan motor 30 flows is narrowed in order to realize the high velocity of the airflow, the flow rate is rapidly reduced due to the resistance.

Because the main fan motor 40 has the characteristics of a small diameter and a high rotation speed, as illustrated in the curve B, the flow rate change according to the static pressure change is small. When the flow rate is large, the static pressure of the main fan motor 40 is lower than that of the sub fan motor 30. Accordingly, when the cross-sectional area of the outlet of the flow passage through which the airflow generated by the main fan motor 40 passes is narrowed in order to realize the high velocity of the airflow, the flow rate is not significantly reduced due to the resistance.

FIG. 18 is a graph illustrating a decrease in flow rate when an accessory is attached to a flow passage through which an air flow generated by each of a main fan motor and a sub fan motor used in a hair dryer according to an embodiment flows.

In FIG. 18 , the vertical axis represents the static pressure, and the horizontal axis represents the flow rate. Curve A represents the characteristics of the sub fan motor 30, and curve B represents the characteristics of the main fan motor 40. Curve R1 represents the resistance of a flow passage when an accessory with low resistance is disposed in the flow passage. Curve R2 represents the resistance of a flow passage when an accessory with high resistance is disposed in the flow passage.

Referring to FIG. 18 , when an accessory having a small resistance is disposed in the flow passage, as can be seen from the curve R1, in the case of the airflow generated by the main fan motor 40, the static pressure P1′ is low, and the flow rate Q1′ is small. In addition, as can be seen from the curve R1, both the static pressure P1 and the flow rate Q1 of the airflow generated by the sub fan motor 30 are larger than the static pressure P1′ and the flow rate Q1′ of the airflow generated by the main fan motor 40. Accordingly, when the flow rate is large, the sub fan motor 30 may be advantageous.

However, when an accessory with high resistance is disposed in the flow passage, as can be seen from the curve R2, in the case of the airflow generated by the main fan motor 40, the static pressure P2′ is high and the flow rate Q2′ is small. Also, as can be seen from the curve R2, in the case of the airflow generated by the sub fan motor 30, the static pressure is high, but the flow rate Q2 is small.

Accordingly, in the case of the main fan motor 40, the accessory with high resistance has a smaller flow rate decrease (ΔQ′=Q1′−Q2′) and a larger static pressure increase (P2′−P1′) compared to the accessory with low resistance. In the case of the sub fan motor 30, the accessory with high resistance has a larger flow rate decrease (ΔQ=Q1−Q2) and a larger static pressure increase (P2−P1) compared to the accessory with low resistance.

On the other hand, a high-pressure and high-velocity airflow is required for hair styling, and a high-flow rate airflow is required for hair drying.

Therefore, because the accessory 100 for styling hair has a large resistance, the accessory 100 for styling may be disposed in the flow passage through which the airflow that is generated by the main fan motor 40 and has a small flow rate change and a large pressure rise flows.

However, for drying hair, the airflow generated by the sub fan motor 30 having a large flow rate and a high static pressure compared to the airflow generated by the main fan motor 40 may be used.

In particular, when the main fan motor 40 configured to generate a high-pressure and high-velocity airflow is simultaneously operated together with the sub fan motor 30 configured to generate an airflow having a large flow rate, such as the hair dryer 1 according to an embodiment of the disclosure, the hair drying may be more effectively performed.

In addition, because the heater 70 and the body printed circuit board 81 acts as resistance to the airflow, the heater 70 and the body printed circuit board 81 may be disposed in the flow passage through which the airflow generated by the main fan motor 40 flows.

According to the hair dryer according to an embodiment of the disclosure having the structure as described above, when using an accessory for styling hair, high-pressure and high-velocity airflow generated by the main fan motor may be used. Therefore, the hair styling may be effectively performed.

In addition, the hair dryer according to an embodiment of the disclosure may use the sub fan motor configured to generate an airflow of a larger flow rate than the main fan motor when drying hair, so that the hair may be dried effectively.

In addition, the hair dryer according to an embodiment of the disclosure may use the high-pressure and high-velocity airflow generated by the main fan motor and the high-flow rate airflow generated by the sub fan motor at the same time, so that the hair may be dried more effectively.

In the above, the disclosure has been shown and described with reference to various embodiments. However, it will be understood by those skilled in the art that various changes may be made in form and detail without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents. 

What is claimed is:
 1. A hair dryer comprising: a body formed in a cylindrical shape and having a first flow passage formed to extend along a longitudinal direction of the body in a central region of the body, and a second flow passage formed to extend along the longitudinal direction of the body outside of the first flow passage; a handle being disposed on a lower portion of the body; a main fan motor to receive air introduced from outside of the hair dryer and generate a main airflow, the main fan motor being disposed inside the handle; and a sub fan motor to receive air introduced from the outside of the hair dryer and generate a sub airflow, the sub fan motor being disposed inside the body, wherein the main airflow flows along the second flow passage, and the sub airflow flows along the first flow passage.
 2. The hair dryer of claim 1, wherein an outlet of the first flow passage is provided at a central portion of one end of the body, and an annular outlet of the second flow passage surrounding the outlet of the first flow passage is provided around the outlet of the first flow passage.
 3. The hair dryer of claim 2, wherein the sub fan motor is disposed at another end of the body.
 4. The hair dryer of claim 3, further comprising: a heater being disposed along the second flow passage.
 5. The hair dryer of claim 4, further comprising: a printed circuit board being disposed inside the handle and configured to supply power to the main fan motor, the sub fan motor, and the heater.
 6. The hair dryer of claim 4, further comprising: a printed circuit board being disposed inside the body and configured to supply power to the heater.
 7. A hair dryer comprising: a body formed in a cylindrical shape and having a first flow passage formed to extend along a longitudinal direction of the body in a central region of the body, and a second flow passage formed to extend along the longitudinal direction of the body outside of the first flow passage; handle connected to the body at a substantially right angle; a main fan motor to receive air introduced from outside of the hair dryer and generate a main airflow, the main fan motor being disposed inside the handle; and a sub fan motor to receive air introduced from the outside of the hair dryer and generate a sub airflow, the sub fan motor being disposed inside the body, wherein the main airflow flows along the first flow passage, and the sub airflow flows along the second flow passage.
 8. The hair dryer of claim 7, wherein an outlet of the first flow passage is provided at a central portion of one end of the body, and an annular outlet of the second flow passage surrounding the outlet of the first flow passage is provided around the outlet of the first flow passage.
 9. The hair dryer of claim 8, further comprising: a heater being disposed along the first flow passage.
 10. The hair dryer of claim 9, further comprising: a printed circuit board being disposed inside the handle and configured to supply power to the main fan motor, the sub fan motor, and the heater.
 11. The hair dryer of claim 9, further comprising: a printed circuit board being disposed inside the body and configured to supply power to the heater.
 12. A hair dryer comprising: a body having a cylindrical shape and having a first flow passage extending along a longitudinal direction of the body in a central region of the body, a second flow passage extending along the longitudinal direction of the body outside the first flow passage, and a heater being disposed along the second flow passage; a handle connected to the body at a substantially right angle; a main fan motor being disposed inside the handle; and a sub fan motor being disposed inside the body.
 13. The hair dryer of claim 12, wherein an outlet of the first flow passage is provided at a central portion of one end of the body, and an annular outlet of the second flow passage surrounding the outlet of the first flow passage is provided around the outlet of the first flow passage.
 14. The hair dryer of claim 13, wherein air introduced from outside of the hair dryer and generated into a main airflow by the main fan motor flows along the second flow passage, and air introduced from the outside of the hair dryer and generated into a sub air flow by the sub fan motor flows along the first flow passage.
 15. The hair dryer of claim 14, further comprising: a printed circuit board being disposed inside the handle and configured to supply power to the main fan motor, the sub fan motor, and the heater.
 16. The hair dryer of claim 1, wherein the sub airflow has a lower pressure, a lower velocity, and a larger flow rate than the main airflow. 